The stem of a sunflower can grow up to 3 m (10 ft) tall and the flower head can be 30 cm (11.8 in) wide. Sunflowers are very fast growing plants, in the right conditions they can grow 8-12 feet (2.4 m - 3.7 m) tall in six months. As of 2012, the Guinness World Record for the tallest sunflower is 8.23 m (27 ft) for a sunflower grown in Germany.